fbgemm_gpu doesn't build for CPU because impl_abstract_pystub is not found

[gshimansky]

I am trying to build fbgemm_gpu for CPU and when I build it I am getting an compilation error that impl_abstract_pystub is not found in line jagged_tensor_ops_cpu.cpp:1661. Looking at the source code https://github.com/pytorch/FBGEMM/blob/main/fbgemm_gpu/src/jagged_tensor_ops/jagged_tensor_ops_cpu.cpp#L1661-L1663 and in all other places where impl_abstract_pystub is used in fbgemm_gpu it seems to be that this call should exist only under HAS_IMPL_ABSTRACT_PYSTUB condition. In this place the same code is copied outside of this condition. Should it be deleted?

[q10]

Hi @gshimansky, thanks for pointing out the bug. This is being addressed in #2363